Nine in the fourth place is a favourable line that most querents will not want. The reading describes leaving something the person still likes, at a moment when leaving is entirely possible and no longer forced, and it makes the good fortune conditional on character rather than on circumstance. The text is blunt that not everyone can do this. A small man, in the classic's own phrase, cannot attain to it, which is a statement about the strength the move requires.
That framing belongs to the period's way of sorting people, and it is left standing here rather than smoothed over. What it is being used to say is that a voluntary withdrawal costs something a compelled one does not, because there is nothing outside the person to attribute it to. They have to supply the reason themselves and then live inside a decision nobody made them take, with the thing they left still visible and still liked.
When the line changes, the upper trigram Qian becomes Xun and the figure becomes Development, King Wen 53, gradual advance through ordered stages, a tree growing on a mountain. The destination answers the question this line leaves open, which is what a willing retreat is actually for. Ground given up on purpose is the beginning of a slow advance somewhere else, and the classic files that advance under a figure whose whole teaching is that it cannot be hurried.